It is well known to use a hand-engageable mouse with a computer keyboard for moving a pointer or cursor on the CRT display of a computer into various positions on the display for one or more purposes. It has also been known to substitute for the mouse a control mechanism which is used adjacent to the keyboard of the computer for effecting changes in cursor positions by manipulation of movable parts by the fingers or palm of the hand while the fingers of the hand remain on the keys of the computer keyboard.
In such a control mechanism, control over vertical and horizontal movements of the cursor on a computer display is achieved by the use of a rotatable shaft and a freely slidable member on the shaft. The member is coupled to the shaft so that the member rotates with the shaft yet the member can be shifted longitudinally of the shaft while the shaft is stationary or while the shaft is being rotated.
A first analog value is adjusted by rotation of the shaft and the member together in either of a pair of opposed directions. A second analog value is adjusted by moving the member along the shaft in either direction. Also, the mechanism can be constructed so that, with a slight downward pressure on the shaft or the member, an electrical switch can be actuated for enabling a circuit of the apparatus with which the mechanism is associated. Such a control mechanism of the type described above is disclosed in U.S. patent application Ser. No. 677,703, filed Dec. 4, 1984.
While the control mechanism described above is suitable for a number of applications, such a mechanism can be simplified so that a control mechanism can be constructed with fewer moving parts yet the simplified control mechanism can provide precision control of a pair of analog values, such as the X-Y position of the cursor of a computer display. The present invention provides such a simplified mechanism.